Issue #665 has been updated by Walter Sonius.

So in the past for intel iGPU the VBIOS CBFS file was copied during build time 
as a copy to EDK2 so it could use it but now EDK2 got improved and it can 
actually read VBIOS CBFS file directly from CBFS but still is limited to intel 
only with the VBT requirement and remains a coreboot/EDK2 buildtime setting?

If I can get rid of the Intel only plus VBT requirement and accept that its a 
buildtime option just for testing may it be possible that it just load/run the 
VBIOS file for the dGPU instead?

----------------------------------------
Bug #665: Does EDK2 MrChromeBox support integrated dGPU uga/gop VBIOS file from 
CBFS?
https://ticket.coreboot.org/issues/665#change-2419

* Author: Walter Sonius
* Status: New
* Priority: Normal
* Target version: none
* Start date: 2026-10-04
* Affected hardware: Apple MacBookPro10,1
----------------------------------------
Does EDK2 MrChromebox 26.09.2 load a VBIOS bin file from CBFS added with 
`CONFIG_VGA_BIOS` and runs it like SeaBIOS does for laptops with dGPU? Tried it 
with and without the `CONFIG_EDK2_LOAD_OPTION_ROMS:y` setting?

For a while EDK2 MrChromeBox payload caries support for loading VBIOS from real 
physical PCIe dGPU's using `CONFIG_EDK2_LOAD_OPTION_ROMS:y` if they have a 
matching 64-bit EFI GOP. This has worked fine for me on real desktop boards 
with PCIe dGPU's from sandybridge to coffeelake both with AMD and NVIDIA dGPU's 
even combined with libgfxinit intel iGPU's.

Currently on coreboot 26.09-14-ge0eec9336f54 for the macbookpro10,1 
[CB:32673](https://review.coreboot.org/c/coreboot/+/32673) it works fine with 
SeaBIOS 1.17. Switching from only Intel to only NVIDIA keeps SeaBIOS bootscreen 
and makes built-in display, both miniDP and HDMI output work if using NVIDIA. 
While only using `CONFIG_VGA_BIOS` with `10de,0fd5` a `uefiextract` supplied 
VBIOS bin and not even using the Kconfig `2nd` or `discrete` VGA options (since 
the Intel iGPU uses libgfxinit).

When using EDK2 MrChromebox 26.09.2 forced to only NVIDIA the built-in display 
remains off during post/boot (no bunny neither on both miniDP ports nor HDMI 
port). However the OS nouveau driver detects the VBIOS in its CBFS/ACPI table 
and all video outputs start working fine including sound output. Currently only 
Intel iGPU output works fine with EDK2 bootscreen.

Any thoughts how to debug or even research if my VBIOS file has a correct EFI 
GOP in it?

By default both EDK2 and SeaBIOS builds are build with libgfxinit support and 
not using the coreboot way of running the VBIOS from CBFS but let the payload 
do it which works for SeaBIOS.



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